Inequality of publishing performance and international collaboration in physics

Using a database of 1.4 million papers indexed by Web of Science, we examined the global trends in publication inequality and international collaboration in physics. The publication output and citations received by authors hosted in each country were taken into account. Although inequality decreased over time, further progress toward equality has somewhat abated in recent years. The skewedness of the global distribution in publication output was shown to be correlated with article impact, that is, the inequality is more significant in articles of higher impact. It was also observed that, despite the trend toward more equalitarian distribution, scholarly participation in physics is still determined by a select group. Particularly noteworthy has been China's rapid growth in publication outputs and a gradual improvement in its impact. Finally, the data also suggested regional differences in scientific collaboration. A distinctively high concentration of transnational collaboration and publication performance was found among EU countries.